H5N1

Delhi air pollution spikes to 100 times WHO health limit

India Today

Via The Guardian: Delhi air pollution spikes to 100 times WHO health limit. Excerpt:

Air quality in Delhi hit severe levels on Friday and a thick toxic smog cloaked the city, marking the beginning of a pollution season that has become an annual catastrophe for India’s capital.  

Schools were shut and non-essential construction was banned around Delhi as the air quality index in the city almost hit 500 – the highest the measurement will go and 100 times the limit deemed to be healthy by the World Health Organization. 

Air quality in the city had deteriorated over the past week, attributed to a sharp rise in farmers in the neighbouring states of Haryana and Punjab burning their fields during the crop planting season, compounded by winds that carried the pollutants into Delhi and a drop in temperatures trapping the particles.  

On Sunday, the state of Punjab saw a 740% increase in farm fires, with more than a thousand recorded in a single day. Other causes of pollution in the city are car emissions, construction and the burning of rubbish at waste plants.  

Delhi, home to about 33 million people, is regularly ranked the most polluted city in the world. According to this year’s air quality life index, compiled by the University of Chicago’s energy policy institute, the people of Delhi could have their lives shortened by 11.9 years due to the poor air they breathe.  

Doctors in Delhi said they had begun to see the damaging impacts of pollution on the city’s residents. “The number of patients with breathing problems has increased, with more people having coughs, colds, watery and irritated eyes, and breathing problems. People of all ages are affected by this. It is time for us to wear masks and go out only when needed,” said Nikhil Modi, a doctor at Apollo hospital in Delhi.

The impact of the COVID-19 pandemic on cognitive decline

Via The Lancet Healthy Longevity, a disturbing comment: The impact of the COVID-19 pandemic on cognitive decline.

The effect of the COVID-19 pandemic on the general population has been catastrophic. Despite substantial progress in understanding the virology, transmission, and pathogenesis of SARS-CoV-2, many of the long-term consequences of COVID-19 or the restriction measures implemented around the world remain unknown. Evidence for the associated adverse effects of isolation, loneliness, post-traumatic stress, depression, fear, anger, and confusion is overwhelming. However, changes in cognitive and physical functioning due to the COVID-19 pandemic have been less well documented.  

Anne Corbett and colleagues used longitudinal data from the PROTECT study to evaluate the effect of the pandemic on cognition in older adults in the UK, exploring various factors associated with changes in cognitive functioning. The use of computerised neuropsychological data collected before the pandemic and during its first and second years enabled repeated measures to be obtained for the same individuals across the pandemic.  

Declines in executive function and working memory were observed across the whole cohort in the first year of the pandemic, including in subgroups of individuals with mild cognitive impairment or a history of COVID-19, and the decline in working memory continued into the second year of the pandemic.  

Although initially thought to cause acute respiratory symptoms, the effects of SARS-CoV-2 on other systems—including the central and peripheral nervous system—is becoming increasingly clear. The new findings from the PROTECT study indicate domain-specific cognitive changes for individuals with a history of COVID-19 that mirrored similar trajectories for those with mild cognitive impairment but with a slightly lower rate of decline.  

This study also highlights reduced exercise, alcohol use, depression, and loneliness as key risk factors that affected the rates of cognitive decline in the older population during the COVID-19 pandemic. The study was observational in nature and therefore causality cannot be inferred, but it would be of interest to elucidate some of the potential biological mechanisms involved in these associations.  

Alcohol intake and lack of exercise could have direct effects on psychological wellbeing and cognitive function; for example, alcohol can inhibit the communication between nerve cells and suppress the activity of excitatory nerve pathways. Unhealthy lifestyles are linked to oxidative stress, which is recognised as a contributing factor in ageing and in the development of neurodegenerative diseases, including Alzheimer's disease.  

However, such lifestyle factors could also mediate direct associations between depression, loneliness, and cognitive decline—for example, depression and social isolation could lead to an increase in alcohol consumption and sedentary behaviour, consequently influencing the rate of cognitive decline through systemic inflammation or reduced mental and social engagement. Longer periods of follow-up—in addition to the availability of key data from before, during, and after the pandemic—are necessary. The wealth of longitudinal cohort studies of ageing in the UK could help to provide some of the necessary answers.  

Looking back, COVID-19 has revealed the astonishing vulnerability of our societies, but also the lack of strategy and organisation from so many governments worldwide, and our shared fragility when confronted with infections. Older people (aged ≥50 years) with cardiovascular disease and complex comorbidities have almost double the risk of being infected with SARS-CoV-2 compared with those without chronic conditions.  

Let us remind ourselves that COVID-19 is not a thing of the past, but a reality for which we must continue to adapt and prepare.

How covid-19 spreads: Narratives, counter narratives, and social dramas

Via The BMJ: How covid-19 spreads: narratives, counter narratives, and social dramas. The key points:

• A flawed narrative that SARS-CoV-2 was transmitted by droplets rather than being airborne became entrenched early in the pandemic 

• Measures aimed at an assumed droplet pathogen (handwashing, surface cleansing, physical distancing) were over-emphasised 

• Measures to reduce airborne transmission (improving indoor air quality, reducing indoor crowding and time spent indoors, and high-grade respiratory protection) were under-emphasised 

• UK policy makers seemed to favour narratives from a narrow group of scientific advisers 

• Consequences included care home deaths, mission critical delays in public masking, and avoidable infections of healthcare workers

The impact of the global COVID-19 vaccination campaign on all-cause mortality

Via NBER: The Impact of the Global COVID-19 Vaccination Campaign on All-Cause Mortality. The abstract:

The global COVID-19 vaccination campaign is the largest public health campaign in history, with over 2 billion people fully vaccinated within the first 8 months. Nevertheless, the impact of this campaign on all-cause mortality is not well understood. 

Leveraging the staggered rollout of vaccines, we find that the vaccination campaign across 141 countries averted 2.4 million excess deaths, valued at $6.5 trillion. We also find that an equitable counterfactual distribution of vaccines, with vaccination in each country proportional to its population, would have saved roughly 670,000 more lives. 

However, this distribution approach would have reduced the total value of averted deaths by $1.8 trillion due to redistribution of vaccines from high-income to low-income countries.